In this paper, a single-server queue with Modified Bernoulli Vacation(MBV) has been considered. The server provides two kinds of services, Compulsory Service (CR) and Non-Compulsory Re-service (NCR). Any new customer who arrives and finds the server engaged, on breakdown, or on vacation will be placed on an orbit; or else if he finds the server free, he enters the service immediately. The server takes a vacation as soon as the orbit is empty at the usual service completion moment. The dissatisfied customer may re-enter the orbit after usual service is complete to receive another service. We have used SVM (Supplementary Variable Method) to derive PGF (Probability Generating Function) for the system. In order to demonstrate the influence that the system parameters have, numerical examples are discussed.

本文考虑了改进伯努利假期（MBV）的单服务器队列。服务器提供两种服务：强制服务（CR）和非强制重新服务（NCR）。任何到达并发现服务器正在使用、出现故障或正在休假的新客户都将被置于轨道上；否则，如果他发现服务器空闲，他会立即进入服务。在通常的服务完成时刻，一旦轨道空了，服务器就会休假。不满意的顾客可以在正常服务完成后重新进入轨道以接受另一次服务。我们使用SVM（补充变量法）为系统推导PGF（概率生成函数）。为了证明系统参数的影响，讨论了数值例子。